1. Field of the Invention
The present invention relates to indoor mobile radio access networks, and more particularly to an indoor mobile radio access network with the capability to adaptively detect and communicate with devices utilizing different service providers and communications protocols. The indoor mobile radio access network can communicate with the different service providers over standard protocols to allow relatively easy integration into existing macro networks.
2. Description of Related Art
Mobile services providers use several techniques known in the art to provide licensed spectrum service in areas of dense population and areas with large signal degradation due to the presence of physical structures such as large buildings. These techniques include the use of femtocells, picocells, or Distributed Antenna Systems (“DAS”) to extend licensed spectrum networks in these environments.
Femtocells provide a highly localized service area and are capable of supporting a small number of users (typically 4-8). Each femtocell connects to broadband internet connections to communicate with a provider's core network. Because each femtocell supports only a small number of users, many femtocells are required to adequately serve a larger number of users. The use of broadband internet means that each femtocell adds additional demand to the network resources of a particular location. Furthermore, femtocells are generally specific to a single wireless carrier, leaving many users without service despite femtocell deployment.
Picocells operate in a similar way to femtocells, but provide access to a greater number of users per cell, allowing for a reduced number of installations to cover a greater number of users.
Distributed Array Antennas or Distributed Antenna Systems (“DAS”) take a different approach to solving the problem of indoor network service. A coaxial cable or fiber optic cable runs from the macro-network base antenna to an antenna element within the building providing an RF analog connection to the macro-network within a building. Since only one antenna or small antenna array is needed to serve the building, some of the deployment problems associated with femtocells and picocells are eliminated. However, since each distributed antenna requires a new coaxial cable or fiber optic line run and installation within the building, the cost of the added infrastructure needed for wide distribution can become prohibitive. Also, the signals obtained in analog form still require processing at the base station so the DAS solution does not address the user load problems also associated with high density areas. In fact, the problem is compounded by adding additional users for the macro-network to process that previously did not have service.
Existing networks suffer performance degradation for users in densely populated areas. Bandwidth limits of individual macro-network base stations and signal degradation due to materials and proximity of large buildings are the two primary causes. These problems have led wireless providers to seek alternative solutions for providing licensed spectrum access to users. It would be useful to have a radio access network solution for high population density areas with closely situated large structures that offers improved service to users, removes load from existing macro-networks, concurrently operates within existing and future communications standards, requires minimal additional infrastructure to deploy, and does not interfere with the existing macro-network.